Add MediaGpuChannelManager::LookupChannel().

media/gpu/ipc/service/media_gpu_channel.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/gpu/ipc/service/media_gpu_channel.h"
 
 #include "base/unguessable_token.h"
 #include "gpu/ipc/service/gpu_channel.h"
 #include "ipc/message_filter.h"
 #include "media/gpu/ipc/common/media_messages.h"
@@ skipping 71 matching lines @@
     Send(reply_message);
   }
 
  private:
   ~MediaGpuChannelFilter() override {}
 
   IPC::Channel* channel_;
   base::UnguessableToken channel_token_;
 };
 
-MediaGpuChannel::MediaGpuChannel(gpu::GpuChannel* channel) : channel_(channel) {
-  channel_->AddFilter(
-      new MediaGpuChannelFilter(base::UnguessableToken::Create()));
+MediaGpuChannel::MediaGpuChannel(gpu::GpuChannel* channel,
+                                 const base::UnguessableToken& channel_token)
+    : channel_(channel) {
+  channel_->AddFilter(new MediaGpuChannelFilter(channel_token));
 }
 
 MediaGpuChannel::~MediaGpuChannel() {}
 
 bool MediaGpuChannel::Send(IPC::Message* msg) {
   return channel_->Send(msg);
 }
 
 bool MediaGpuChannel::OnMessageReceived(const IPC::Message& message) {
   MediaGpuChannelDispatchHelper helper(this, message.routing_id());
@@ skipping 68 matching lines @@
                           params.output_profile, params.initial_bitrate);
   GpuCommandBufferMsg_CreateVideoEncoder::WriteReplyParams(reply_message,
                                                            succeeded);
   Send(reply_message);
 
   // encoder is registered as a DestructionObserver of this stub and will
   // self-delete during destruction of this stub.
 }
 
 }  // namespace media